Data labelled ‘National Rail’ is calculated by summing the number of journeys for the last seven days and expressing this as a percentage of the equivalent pre-Covid-19 week in 2019 or 2020.
Whilst considered fit for purpose for monitoring overall change in usage trends, there are several features of LENNON journey data which should be borne in mind when using it for this purpose. These are mitigated to some extent by reporting the data as a percentage of 2019 (or 2020) rather than reporting journey numbers themselves.
Adjustments have been made for bank holidays in England and Wales where an equivalent comparator date is available to use. On some occasions, such as over the Christmas and New Year period, when bank holidays have been moved, or when new bank holidays have been added, data have been suppressed because there is a lack of equivalent comparator date available to use. Because the published data is a seven-day rolling average, data for the days following a date which has been suppressed can be based on a rolling average with fewer than seven days of data. The impact of industrial action or other unexpected events which affect rail usage are not adjusted for. This means caution should be made when interpreting figures for specific days, especially when only one of either the post- or pre-pandemic dates contain a bank holiday. Such cases are flagged in the notes of the publication table.
LENNON daily passenger journey estimates and ticket sales are sensitive to occasional lump sum adjustments. For example, TfL issue zonal season tickets which allow travel on National Rail. Earnings from these journeys are passed between TfL and train operating companies via LENNON. When these earnings are reported and dropped into LENNON, this could look like a considerable change in journeys or sales on a given day. Again, this supports looking at rolling weekly totals and comparing to the equivalent week in 2019.